New sensor can "feel" clothes

A scratchy cardigan triggers different sensations on the skin than a delicate silk blouse. If these properties are to be determined objectively and reproducibly, for example in order to develop new textiles, reliable analytical methods are asked for. Empa researchers, together with the Laboratory of Textile Physics and Mechanics at the Université de Haute Alsace in Mulhouse, have developed an optical sensor that is suitable for this purpose.

To enable the sensor to detect the tactile properties of a surface, the researchers took the human fingertip as a model: Concentric grooves in the micrometer range cover the optical polymer fibers developed at Empa's Laboratory for Biomimetic Membranes and Textiles in St. Gallen. If the fibers are subjected to mechanical stress when touching a textile surface, the intensity of their light transmission changes. Once developed successfully the sensor would render surveys with test persons – which are notoriously subjective – superfluous. "Such a sensor, which works like a digital fingertip, can significantly reduce development times for new textiles," says René Rossi, head of Empa’s Laboratory for Biomimetic Membranes and Textiles.